Electric switch.



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To all whom it may concern Be it known that I, FREDERIG BARR, a citizen of the United States of America, and residing at New York, in the county of Kings and State of New York, have invented new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates particularly to mechanism adapted to be operated by means ofv a pull cord or chain as it is commonly termed. One object is to provide a simple and inexpensive mechanism in which the parts are housed and electrically insulated so as to avoid the possibility of short .circuiting or grounding. I

Another object is tol provide a construction which can be readily assembled and readily wired or disassembled when desired. Another object is to prevent or reduce arcing at'the contacts in. breaking the circuit.

In the form shown the pull switch mechanism is carried by an insulating block provided with flanges for spacing apart and in sulating the terminals and switch contacts. The insulating block and the switch mecha nism are housed in an insulating receptacle having an opening at the back to receive the mechanism and a passagethrough the front to serve as a guide for the chain. The preferredform of switch mechanism is of the rotary ratchet type in which a rotatable 'switch member having a plurality of spring I more inclined stationary switch contacts arms is rotated step by step over one or and inclined insulating steps or faces. I

, have discovered that the arcing at the break can-be practically eliminated so that the switch will run cold and without injury fan shape wider at the free ends so that when the rotary switch member is rotated and the circumferential length of the contact area decreases, the width of the contact area and thus maintain a sufiicient area of contaotto properly conduct the current Without heating the contacts.

Figure 1, 1s a vertical section showing the mechanism in its normal position of rest. Fig. 2, 15 career view of the insulating base or receptacle portion. Fig. 3, is a rear view of the switch block and circuit terminals. Fig. 4., is; anedgeview and partial section of the same. Fig. 5, is a view of the I Specification of Letters Patent. Patqgntgd; ltlay 19, 1914 Application filed December 16, 1912. Serial No. 736,921.

I rear side ofthe switch carrying block. Fi

6, is a view of the frontside of the switch carrying loloclr the rotary and oscillating parts being removed. Fig. 7, is a face view of the rotary switch member and its -insulating carrier. Fig. 8, is a detail view of one of the stationary switch contacts.

"The receptacle or base 1 is preferably formed of insulating material such as porce- 18.111 and the switch carrying block 2 also of insulating material tits in a recess 3 in the.

rear of the base. The base has an opening 4 at the front serving as an insulating guide for the pull chain. 5.

The inclined switch contacts 6 and 7 are arranged on opposite sides of the spindle 8 which is rigidly mounted in the block 2 by means of the slotted head 9 on one end of the spindle and the nut 10 screwed on to the spindle on the opposite face of the insula'ting block. Between the segmental switch contacts fiend 7 are the inclined steps 11 and 12. The circuit terminals are formed so as to have feet 13 and 142 secured in contact with the feet of the switch segments by screws 15 and 16. The side arms 17 and 18 are turned at substantially right angles to the feet 18 and 14 and the outer ends19 and 20 are bent over into recesses 21 and 22 for the binding screws-and the connection of the circuit wires. Narrow flanges of insula't ing material 23 and 2e protect parts of the edges of the circuit terminals and other flanges 25 and 26 protect other parts of the edges of the circuit terminals. A flange 27 extends around the front of the insulating block 2 above the switch contact segments 6 and 7. An insulating disk 28 is vmounted to rotate on the spindle and has-a centralboss 29 and a peripheral flange and serves as a carrier for the rota-table switch member 31 having the spring arms '32 and 33. A. ratchet operating lever 23% is mounted; on the spindle for turning the carrier 2'8 and spring Contact member 31 step by step. A notched nut 35 is screwed on to the outer edge and a spring 36 is interposed between the nut 35 and the ratchet plate 3.4 so asto press the ratchet lever against the carrier and also tends to ,hold the parts inthe position shown in Fig. 1 where the ratchet lever is pressed against the stop shoulder 37 of the insulating block. The flange 38 guards the end 01 the chain where it is attached to the operating" lever 34: so as to prevent it from being accidentally die- Eli ltd

engaged. A flange 39 over-stands the entire switch mechanism and serves to close the back of the opening 3. The base is also preferably provided with a groove 40, the

. The stationary switch' contacts as before walls of which serve as a guard for the end of the spindle :8, the nut 5 and the spr ng 36 so as to prevent the chain from becomlng entangled therewith. When the parts are assembled, the walls 41, 41-, form one side of the groove while the flange 27 forms the other side of the groove for the chain and theoperating ratchet lever. When the parts are assembled it will be noted that the circuit terminals are inclosed between adjacent walls and flanges of the insulating base and insulating block. The circuit may be traced through the parts 19, 17- andof'one c rcuit terminalto the switch contact 6, across the rotary switch member 31 to the switch contact '7, and then through the -parts' 14, 18 and 20 of the other circuit terminal.

' intimated arepreferably inclined and resilient similar to the arms 32 and 33 of the rotary switch member.. In order to make these switch contacts and the switch member to wearand carry the necessary current, it isnecessarj to make them of ratherthick material. When the material is thick it is diflicult to make it sufiiciently resilient unless the arms are made comparatively narrow.

- its flanges and recesses necessary for. the

This has been found to give insufficient area of contact just before the break. As a result the-contacts heat u and thus tend to produce an rc at the brea I have found that this can e, avoided by making the contact arms of fan shape, wider at theend. This insures sufiicient area of contact even where the arms are stiff and do notbear perfectly fiat upon each other.- By this construction while the ends'of the arms are wide enough to carry the necessary current so as'to prevent over heating and arcing, the bases of the arms are sufficiently narrow to make the arms resilient even though of comparatively heavy material.

It will be noted that the insulating base and its-interior recess, chain guiding passage and insulatingwalls is so designated that it can be readily made of porcelain or a similar material by a simple die action. It will also be noted that the insulating block and structure.

This

rially effects not only the cost of construction but accuracy of location of the parts as n ell.

What I claim is 1. In an electric pull switch, an insulating support consisting of an insulating base provided with a recess in the rear thereof;

and an insulating block removably fitting in the said recess, said insulating support having terminal recesses in the rear face thereof and the insulating base having a chain guide passage inthe front thereof-in line with the rear recess therein, switch mechanism carried by the insulating block' including an operating chainpa'ssing out through the chain guide passage at the front, circuit terminals extending rearwardly from the switch mechanism and term'inating'in angular ends seated in the terminal recesses in the rear face of-the' insu lating support and binding screws engaged in said angular ends'and thereby accessible at the rear face of the switch structure.

2. In a pulllswitch, the combination of an insulating basehaving a recess open at the rear a chain guide passage at the front,

an insulating block removably fitting in said recess from the rear, switch mechanismcarriedby said block and including a spindle and an opera ting chain guided in said chain guide passage, said ,insulating base havinga groove to receive the end' ofthe spindle, the walls of the groove acting to guard the spindle from said chain.

3. In a pull switch, an insulating base having a recess open at the rear, a chain guide at the front, an insulating block removably fitting in said recess and held against movement when seated therein, switch mechanism carried by said block including an oscillating operating lever and a chain, said base and said relative stationary block having integral fixed walls forming between them a guiding groove for the op-,

erating lever and the pull chain.

4. In a pull switch, an insulating base 'havinga recess open at the rear and a chain guide open at the frpnt, an insulating block .removably fitting in said recess, switch mechanism carried by said block including an operating \chain guided in said' chain guide, saidblock having an integral flan extending across in rear of'the switch mec anism to thereby cover the switch mecha-' I nism at the rear and circuit terminals extending r'earwardly from. the switch mechanismto the rear side'of the flange to be thereby accessible at the rear of the switch 5. In a pull switch, an insulating base having a recess open at-the' rear and a chain guide passage at the-front, an'insul'ating block r'em'ovably :fitting in said recess, switch mechnm sm earned by saidblock including S'Wltl'il contacts and an operating menace chain, said insulating block having mutually cooperating insulating flanges forming an. insulating chain guiding groove and preventing said chain from engaging with said contacts. Y

6. In .a pull switch, an insulating block, switch contacts carried thereby, a switch member adapted toconnect said contacts, a

'pull chain tor-cperating said switch memcircuit terminals connected to said her, switch contacts, each terminal consisting of a foot for engaging a contact, an arm extending atright anglesto the foot and an outer end bent at right anglesto said arm and having a binding screw, said block havin -flanges guarding the opposite edges of for the hindsaid arms and having. recesses ing screws. 4 I v '4". Ina pull switch, a receptacle having a recess open at the rear and a chain guidthe front, aninsulating block removaoly fitting in said recess, and switch mechanism carried by said block at one face thereof including a pull chain through said chain guide, circuit terminals in the edges of said insulating block extendcontact whereby extending in rearwardly'heyond the rear face of the block and hindin screws engaged in the rearwardly exten ed portions of the circuit terminals at the rear side of the block.

8. In an electric switch, a fan-shaped in- :clined segmental switch contact narrow at the base of the incline and increasing in width to the free end and a rotatable switch member having inclined resilient arms of fan-shape narrow at the base and increas:

resilient arms resting on said segmental switch contact with the broad end of said arm contacting with contact when the circuit is closed, the rotation of said switch member causing said arm to slide around on said segmental switch the broad end of said arm is gradually brought into engagement with the broad end of said contact just before the circuit is opened.

. riinnnnrc BARR. Witnesses Roar. S..ALLYN, E. Bnanronn.

the narrow base of said ,ing in width to the free ends, one of said 

